The July 30 shark attack at Ballston Beach in Truro has focused national attention on the seasonal occurrence of white sharks in waters close to Cape Cod and Island beaches. White sharks are no strangers to residents here; I certainly won’t forget kayaking with friends to see a female white shark trapped in a coastal pond on Naushon island in September 2004. There seems little doubt that we have witnessed more white sharks in areas frequented by swimmers along the eastern shore of the Cape over the past few years.

An abundant food supply, safe habitat and management protection that began years ago has contributed to the resurgence of seals in Island waters.

Gray and harbor seals are back. Though marine experts at the federal level don’t have actual numbers, there have been many reports this summer of seals around the Island. In short, not all bathers at the beach are humans.

It’s been 35 years since the movie Jaws forever linked great white shark attacks and Martha’s Vineyard in the popular imagination of the world, yet in all that time no one has ever been attacked.

Then, long after all thought it was safe to go back in the water, along came the U.S. Coast Guard with last week’s holiday boating advice, headed “Shark Advisory” and warning swimmers, kayakers and small boaters of the danger of great white sharks.